Files
dvc/dvc/utils/serialize/_common.py
T
Laurens Duijvesteijn 9a7b6d2a1a serialize: Wrap UnicodeDecodeErrors (#6193)
Also expose `encoding` and `path` as attributes, so programmatic
consumers can access it easily.
2021-06-19 11:35:50 +05:45

84 lines
2.2 KiB
Python

"""Common utilities for serialize."""
import os
from contextlib import contextmanager
from typing import TYPE_CHECKING, Any, Callable, ContextManager, Dict, Union
from funcy import reraise
from typing_extensions import Protocol
from dvc.exceptions import DvcException
if TYPE_CHECKING:
from dvc.fs.base import BaseFileSystem
from dvc.types import AnyPath
class DumperFn(Protocol):
def __call__(
self, path: "AnyPath", data: Any, fs: "BaseFileSystem" = None
) -> Any:
...
class ModifierFn(Protocol):
def __call__(
self, path: "AnyPath", fs: "BaseFileSystem" = None
) -> ContextManager[Dict]:
...
class LoaderFn(Protocol):
def __call__(self, path: "AnyPath", fs: "BaseFileSystem" = None) -> Any:
...
ReadType = Union[bytes, None, str]
ParserFn = Callable[[ReadType, "AnyPath"], dict]
class ParseError(DvcException):
"""Errors while parsing files"""
def __init__(self, path: "AnyPath", message: str):
from dvc.utils import relpath
path = relpath(path)
self.path = path
super().__init__(f"unable to read: '{path}', {message}")
class EncodingError(ParseError):
"""We could not read a file with the given encoding"""
def __init__(self, path: "AnyPath", encoding: str):
self.encoding = encoding
super().__init__(path, f"is not valid {encoding}")
def _load_data(path: "AnyPath", parser: ParserFn, fs: "BaseFileSystem" = None):
open_fn = fs.open if fs else open
encoding = "utf-8"
with open_fn(path, encoding=encoding) as fd: # type: ignore
with reraise(UnicodeDecodeError, EncodingError(path, encoding)):
return parser(fd.read(), path)
def _dump_data(path, data: Any, dumper: DumperFn, fs: "BaseFileSystem" = None):
open_fn = fs.open if fs else open
with open_fn(path, "w+", encoding="utf-8") as fd: # type: ignore
dumper(data, fd)
@contextmanager
def _modify_data(
path: "AnyPath",
parser: ParserFn,
dumper: DumperFn,
fs: "BaseFileSystem" = None,
):
exists_fn = fs.exists if fs else os.path.exists
file_exists = exists_fn(path) # type: ignore
data = _load_data(path, parser=parser, fs=fs) if file_exists else {}
yield data
dumper(path, data, fs=fs)